The present invention relates to dental instruments and more particularly to dental instruments for use in tooth structure reduction operations.
In the course of dental repairing operations such as the reduction of tooth enamel for the fitting of a jacket crown or the provision of a suitable opening in the tooth for an inlay or filling, the dentist commonly employs a handheld power driven grinding tool. Such grinding tools usually comprise a rotary driven shaft having a shank portion provided with an abrasive coating on its peripheral face which serves as the grinding portion. Ordinarily, due to the frictional engagement of the instrument grinding portion therewith, substantial heat is produced at the tooth surface which can cause substantial patient discomfort. Such grinding action also requires the application of steady pressure of the grinding portion against the tooth enamel dentin or filling necessitating prolonged and constant exertion by the dentist, to the detriment of both the patient and the dentist's work efficiency.
The above-mentioned disadvantages have been found to be virtually unavoidable in the use of currently available dental grinding tools because the design of their grinding portion does not permit the rapid reduction of axial walls occlusal surfaces in crown preparation or the rapid opening or extending of new cavities, or in the removal of old composite or amalgum fillings.
It has also been found that in the use of conventional tooth grinding tools, tooth debris formed during axial wall reduction and cavity preparation operations tend to accumulate and clog the sharp corners and crevices in the working portion of the tool thereby impairing the cutting quality of the tool and substantially reducing tool life.
It is, therefore, an object of the present invention to provide a dental reducing tool which enables rapid reduction and penetration of the tooth structure with minimal generation of heat on the tooth.
It is a further object of the present invention to provide a dental reducing tool of the character described which minimizes accumulation of tooth debris on the tool and facilitates efficient removal of such debris which may have formed thereon during the various tooth structure reducing processes.